Boring-tool.



C. H. SCHMIDGALL.

BORING IDOL. APPLICATION FILED JULY 16.1911.

Patente Mar. 18,1919.

CARL EL SCHMIDGALL, OF PEORLA, ILLINOIS.

BORNG-TCOL.

Specification of Letters Eatent. Patented bien. lg, digiti Application led July 16, 1917. Serial No. 181,443.

To all whom t may concern Be it known that l, CARL H. SCHMIDGALL. citizen of the United States, residing at Peoria, in the county of Peoria and State of Illinois, have invented certain new and useful improvements in Boring-Tools; and I do hereby declare that the following vis a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the saine.

This invention relates to a tool for boring holes whose walls describe a polygon, or whose walls may describe curves, adapted for boring in wood or metal.

The' primary object of my invention is the provision of a tool which by its form will at one operation bore a hole of a predetermined form.

Other objects and advantages will appear in the following specification besides certain details of construction all of which will appear herein aided by the accompanyingl drawing which shows one of the embodiments of my invention, it being understood that changes may be made that will lie within the meaning and intent of the invention and such as will fall within the scope of the appended claims.

Figure 1 is an elevation of thecomplete tool, 4

Fig. 2 is a longitudinal section of thetsaine. Fig. 'shows the tool as seen from the top.

Figs. 4c and 5 are plans of modified formsv of the tool seen in plan.

The body of the tool preferably comprising a handle portion 1 having at one end a cavity i2 with which communicates a longitudinal bore 3. Within the bore is designed to rotate shaft which preferably extends from one end of said body, and it is provided within the described cavity 2 with a miter-gear 5 suitably aiiiXed to it.

ln the first thrceiigures that portion of the body having the cavity 2 takes a square form as viewed in plan, 8, and in each of the Malls created by said cavity is a bore G. Fig. 2, cach of which ymay receive a hardened bushing 7 to form a bearing for short shafts S whose axes are perpendicular to the axis of the shaft 1i. Each is provided within the cavity 2 with a pinion-gear 9 arranged/to mesh with the described gear 5.

10 is a cap or closure for the cavity 2 secured to the end of the body by any suitable means such for example as screws l1, Figs. 1 and 3, said cap or closure including within the cavity an extension 12. This said extension may answer two purposes-that of providing a bearing for the described extension of the shaft 4, and also for the inner ends of the described short shafts S. The latter are slightly reduced in diameter at their inner ends and rotate within sockets 13 in the said extension 12 and are threaded to receive their respective pinion-gears 9.

Adjacent the described threads each shaft is furnished with an enlarged portion 14 adapted to have a running fit in the described hardened bushing 7. Gutward from the enlarged portion the shaft is threaded to screw into a correspondingly threaded i-ore 15 of a cutter 16 having in this instance the form of a cone. The described cutters are fiuted as clearly shown in Fig. 1, the cutting edges of each of the cutters being so disposed with regard to their direction of rotation as to properly engage the work.

In assembling the tool after the shaft i and its gear 5 have been placed in position, the pinion gears 9 are dropped into the cav ity 2 and the cap or plate 10 secured in posi" tion. The short shafts 8, each of which provided with a screw-driver slot 17 at its outer end, are then inserted through the bushing 7, and screwed into the pinion-gears 9 which being in mesh with the miter-gear 5 'can be held from rotating at this time by grasping andpreventing the shaft si from rotating. As this operation is performed theinncr ends of the shafts are projectml into the sockets 13 which form bearings for the same.

After the shafts areserewed home 7 the cutters are run upon the threaded outer ends of the shafts and the tool is ready for work.y

readily take the lateral pressure imposed by the cutters when atavork without undue trim the Wear of the shafts 8 and when worn may be replaced hy new ones, the shafts themselves being also 'replaced when they become Worn. Likeu/iss the cap l0 may he replaced for like reason. By this arrangement the body l is never demaged or rendered unt for use by Wearing and need never he reinoved, all parte subject to Wear losing= renewable.

rllhe shaft niay terminate within. the extension l2 or it may extend through the cap or closure l0 shown and niay receive a sleeve 18 or other suitable part which may he suitably secured. to it, said sleeve forming a socket for the of :an auger-hit 19, boring tool, or a drill, 20 's a eollarsuitahly secu-red on the shaft l and spaced from the handle-portion. interposed between said collar 2U and handle-portion. 22 indicates a series ofl balls intierposed between the collars 2l, and 23 is a bllieteiner. Since the applied piessure is upon the shaft 4, when the cutters lo are at Work, the vcollars 21 and balls 22 torni. thrust hearings which permit the gears 5 and 9 to Work freely. Whenthe boring element 19 only is at Work prior to the engagement of the cutters '16 with the Work the thrust bearings are of course not in use since at that time 4the shaft Lland element 19 areas a single part.

24 is an arm of any suitable form secured upon the handle portion i hy which to sup port the tool in an upright position during operation. I

in the forni snor-fn in the three ligures wherein, stated, the body is square in form, by means of a drill, hit, or other tool, a hole is irst drilled in the material in which the hole is to he formed, the dian1 eter of the said drill, hit, or other tcol being substantially equal to or slightly larger than the diagonal measurement of said body, as indicated hy the circle shown by a broken line a in 3,

lt is observed ti et each cutter has a, dianieter at its hase shout equal to the 'Width oit` each face of the body opposite which it lies so that a line dijawn hetween the apices of any two adjacent cutters will just pass t' e corner of the oody and that, as in the tig last referred to, e perfectly square hole .will he cut in the wei-lz; indicated at X.

ln Fig. 4 the body indicated at A takes the form of an equi-lateral triangle having on each of its faces a cutter B corresponding 1 to 16 in the other figures, though of necessarily slightly different form, that is having steeper sides to form acute corners instead of right angles as used in cutting e square hole.

' InFi'v. 4 the dotted line B indicates the size of the bore to be made by the auger-oit and in Fig. 5 the dotted line F indicates the sizeof hole for the particular size of tool 2l, 2l indicate tvfo collars' Lewy/ie in that ligure, it being ohserif'ed that in each case the hole to be bored is of a diameter large enoilgh to receive the body of the tool, the cutters clearing' out the material necessary for the hole of the required forni` ln Fig". 5 the body represented at C is in the forni of a hexagon from each et Whose faces projects a cutter D whose 'edses meet at the corners of the hexagon. This structure makes a hexagonal hole E in the Work indicated at l?.

` My tool may he furnished with the augerloit i9 describe-:l out this may not he used in conjunction,y since a separate augenhit may he employed. to core a hole to he afterward shaped or Worked out by the cuff'v The cutters i6 -ipe ite in either metal orf 1Wood and when Working in the latter they carry up, hy means of the eut-ting edges thereof, the chips constantly forced up by the hit i9. ln yf'oiiing in instal, of course, a suitable drid seplaces the hita The tool is not confined to making open ings having or straight Walls since the cutters may have curved times whereby they may he adapted for cutting holes having' curved Walls 'for example.

The tool is ot great value in making Wrenches commercially, the square, hexagonal or octagoual holes, as the case may he, being formed rapidly and accurately. llt also ci. velue in making holes of various shapes ttor special purposes. The Working parte of tool are thoroughly proteceed trom the cuttings olf the material. in that the closure .1.0 tightly covers the recess 2, The shafts are the only porions extending ircro. the cody hit these rotate in closed bea lgs the ma those point terial cannot enter at The advantage in niountinfc' the shafts so as to have tive hearing points admits of the gears 9 lyingl between them. There can he no lateral strains, therefore, from the gears upon the shafts thus supported such as to cause binding or springing thereof. Fun thermore, the cutters which 'would under work naturally set up lateral strains upon the shafts cannot cause the latter to hind in their hearings.

t is orefecred to screw the gears 9 upon the sheits since hy that ineens thee no danger of the seid shafts slipping mit of the gears, it he' understood that when 'i closure i() is iu n position, the shafts must necessarily he introduced into their respective Gears. Since the direction oi? rotstion of the is elocl -Wisethey will tend to tighten upon the shafts due to their threadedengagement therewith.

As previously stated, changes may he made that may suggest themselves to the practical person since it is not my Wish to he confined to what is described and shown, which is merely the preferred Way.

'liti Having thus described my invention, claimzl. A boring tool comprising, in combination,`a body including a bore terminating in :1 recess, a drive shaft in said bore, a gear on said shaft within the recess, a part eX- tending into the recess spaced from the Walls thereof, a series of shafts having their bearings in the body and said part, e gear on cach shaft of the series between the walls of the recess and the said part and in mesh with the first named gear, and a cutter on each shaft outside the body.

2. A. boring tool of the type described including in combination, a bodyvhaving a bore, and a recess at one end communicating With the bore, a, shaft journnled in said bore including a gear lying in said recess, a closure Afor the recess including en eXtension lying within the seid recess spaced from its Walls, a series of shafts journaled each at one end in the extension, and also journaled near its other extremity in the Wall of the body, e. gear on each shatof the series between the extension and said Well androtatable with said shaft, and a conically termed cutter secured on the extremity of each shaft outside said body. 1n testimony whereof aiix my signature, in presence of two Witnesses.

CARL H. SCHMDGALL. Witnesses:

L. M. THURLOW, ARTHUR KE'ITHLEY. 

